lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Fri, 9 Dec 2022 00:50:26 -0500
From:   "Theodore Ts'o" <>
To:     Ye Bin <>
        Ye Bin <>, Eric Whitney <>
Subject: Re: [PATCH v4 2/3] ext4: record error when detect abnormal

On Thu, Dec 08, 2022 at 11:34:25AM +0800, Ye Bin wrote:
> From: Ye Bin <>
> If 'i_reserved_data_blocks' is not cleared which mean something wrong with
> code, free space accounting is likely wrong, according to Jan Kara's advice
> use ext4_error() to record this abnormal let fsck to repair and also we can
> capture this issue.

If i_reserved_data_block, it means that there is something wrong with
our delayed allocation accounting.  However, this accounting is
usually only an in-memory error.  The one exception is if quota is
enabled, in which case the space is decremented from the
user/group/project quota.

However, if quota is not in use, which is the overwhelmingly common
case, there will be nothing for fsck to repair.  (It does mean that df
will show a slightly smaller free space value due to the messed up
delayed allocation accounting, but that disappears after a reboot.)

Marking the file system as in need of repair when nothing is actually
wrong with the on-disk file system can backfire, in that it confuses
users when they see the ext4 error but then when they run fsck, fsck
reports nothing wrong --- at which point they file a bug.

We could use ext4_error if quotas are enabled, and ext4_msg if not,
but it might not worth the extra complexity.


					- Ted

Powered by blists - more mailing lists